The Delaware company filed suit Monday asking that it be allowed to remove the equipment that it leased to the muffler shop.

The shop on University Drive south of Griffin Road was destroyed by a powerful explosion that reduced it to rubble. Four people were killed and eight others injured, one critically.

Texgas attorneys argued that an investigation by the state fire marshal and the federal Bureau of Alcohol, Tobacco and Firearms already has excluded the propane tank and connecting equipment as a factor in the explosion.

``The tests and findings of the above agencies determined that the equipment owned and leased by petitioner Texgas Corp. was not defective,`` the lawsuit said.

The accident investigators last week did say the cause of the blast was a propane gas leak, but have not determined how the gas escaped into the shop or how it was ignited.

Attorneys Amy Rubin and David Wilensky, representing the muffler shop and the owner of the property, said they want to conduct their own independent tests of the propane equipment.

``They don`t want anyone else to have the right to do the test under the same conditions,`` Rubin said.

He contended the tank was not dangerous. If Texgas wished, she said, it could drain the tank or otherwise neutralize the safety risk entirely without actually removing the tank.

Price said the tank is a valuable piece of evidence for future lawsuits filed in the matter. Initially, however, he proposed that the tank be taken into custody by the fire marshal to give other experts a chance to examine it.